Urbanites' outdoor thermal comfort in the informal urban fabric of warm-humid Dar es Salaam, Tanzania

In warm humid tropical climates, the outdoor environment defines the lives of the majority of the population in terms of social and economic aspects. Improvement of the outdoor thermal environment encourages social and economic prosperity of the urbanites. This paper explores urbanites' thermal comfort in the informal urban fabric of warm humid Dar es Salaam, Tanzania. Simultaneously, the study conducted micrometeorological measurements and a questionnaire survey consisting of 1541 respondents for both the warm and cool seasons. The thermal indices, Standard Effective Temperature (SET*), Universal Thermal Comfort Index (UTCI) and Physiological Equivalent Temperature (PET) were calculated. Results show that urbanites of the informal urban fabric areas experience both narrower and higher thermal comfort ranges when compared to both similar climates and other types of climate in the formal urban fabric context. Thermal acceptable ranges were found to be 30.2 - 32.5 degrees C and 23.4 - 27.4 degrees C for UTCI and SET* respectively. Despite the fact that the results showed the high adaptive capacity of the urbanites, they also revealed the urbanites' tolerance to high thermal index temperatures due to the limited adaptive options available within the informal urban fabric morphology. The study findings could contribute significantly to the upgrading of informal settlements.